CXCL8 and chronic obstructive pulmonary disease: Increases in the concentrations of adiponectin, c-reactive protein (CRP), fibrinogen, leukocyte count, IL-6, interleukin-8 (IL-8), TNF-α, and Chitinase-3-like protein 1 (YKL-40) have been reported with the progression of COPD [91,92].